Could you attend a wedding in good conscience, knowing from the getgo that the couple was going out of their way to be rude to their guests in every single aspect and honestly do not care who they offend? They are using the excuse of "well everyone else does it and it goes off perfectly" and "who are these idiots who write etiquette books and what are their credentials to make the claims that they do?" Meanwhile when you do speak up about it, you are guilted into the bad guy who doesn't know what you're talking about according to the couple in question or anyone around you, since "you aren't suppportive of any of it, or the couple themselves and you ought to be ashamed of yourself", regardless of whatever you may feel toward them, all rudeness aside.
This situation is happening to a friend of mine and she has mentioned that her family is even torn apart and has disowned her because they don't understand why she is not supporting the couple who is doing this (who is part of her immediate family and is expected to attend this event). She's completely devastated due to how she is being treated, and I honestly don't blame her. But at the time, I really don't know what to say to that kind of thing to make her feel like she isn't crazy. Most people would justifiably feel like they were losing their mind if their family turns their backs on them like that. What would you do if you were in a situation like this or knew someone who was?